Bill Easterly vs. Jeff Sachs: What percentage of the recipients didn’t use the free malaria bed nets in Zambia?

[Bill Easterly in his 2006 book] went on to write that “a study of a program to hand out free [malaria bed] nets in Zambia to people … found that 70 percent of the recipients didn’t use the nets.” Yet this particular study, which was conducted by the American Red Cross and CORE, actually showed the program was a success, with high rates of net adoption.

I followed the link and took a quick look at the study, and indeed in the intro it says, “Household ITN coverage increased from 28.9 percent (pre-campaign) to 85 percent (with a greater than 80 percent coverage across all wealth quintiles). . . . At six months post-campaign . . . and 60 percent of the pregnant women and children under 5 years old were reported to have slept under the net the previous night.”

60% of 85% is far from ideal but it’s a lot higher than “70 percent of the recipients didn’t use the nets.” But I am no expert in this area, so I sent a message to Easterly asking if there was actually a different study that he was referring to in his book.

Easterly replied:

My book footnoted a PSI study on social marketing of bed nets (“the Malawi model”) right before the Zambia sentence. [The footnote is 18. “PSI Malaria Control, the Malawi ITN Delivery Model,” February 2005.] The book does not give the 2004 study Sachs mentions as a source.

Through Google, I found the document right away. But I couldn’t find where it said that 70 percent of the recipients didn’t use the nets. It would be helpful for me to track down this particular point, just as a way of getting a better understanding of this debate.

P.S. I’ve met Sachs and Easterly (at different times) and respect them both but don’t know either of them well. Also I am working on a project with Sachs and am affiliated with his Earth Institute.

P.P.S. Someone writes in:

So far the only thing I found in that document was this:

I guess if you look at Feb 2004 pregnant women, coverage is only 34%, which means 66% are not sleeping under bed nets, which is close to 70%?

For a more recent study, see p.18, Table 2, the mean of the free group usage conditional on take-up is 70% (take-up looks like 99%, see p.17).

8 Comments

I note that the paper you linked to has the date April, 2005. The quoted text references a February, 2005 paper. The paper has no reference to Zambia; and, judging from its contents, such a reference would be unlikely.

A report that appears to have been printed in 2005 states the following regarding Zambia:Six months after the campaign, 97% of ITNs distributed remained in the households that received them, and 70% of children under five years had used an ITN the previous night

I have a long, socio-cultural explanation for why economists care so much about usage for freely distributed bednets – but let me just say that it has all the things development micro-economists are interested in: valuation of products that limit risk, large scale public externalities, investment in human resources, and funny behavioral responses that allow people from any perspective to basically claim how right they are about how to help poor people.

I can’t find the 70% number either, but it could be some combination of these numbers – who knows what stat was where in what version, but you could imagine it was something like “year round usage for children of owners who were given free bednets” or some such:

“Usage figures are significantly lower than for ownership. Only 41% of all nets owned were actually slept under the previous night, with only 20% of all children under five and 21% of pregnant women reportedly having used a net the previous night. This may be related to the fact that the survey was conducted in October-November 2005, at the end of an extended dry season when temperatures were high and mosquito biting densities low – heat and the absence of mosquitoes were the most commonly cited reasons for not sleeping under a net. Only 18% reported that their children under five sleep under a net all year round (compared with 71% for the rainy season).”

At least on the Amazon preview of the Easterly book (p12) it says that a study of the Zambia free nets program “found that 40 percent of the recipients didn’t use the nets”. i.e. not the 70% that Sachs quotes.

That part of Easterly’s book is contrasting free with subsidized schemes, and arguing in favour of the latter. So the “Malawi model” is the sort of thing that Easterly’s supporting here.

I can’t find a source for the Zambia claim in Easterly’s book, though (and the 2004 study link doesn’t work for me so I can’t tell what’s going on there).